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-rw-r--r--arch/mips/include/asm/atomic.h267
1 files changed, 267 insertions, 0 deletions
diff --git a/arch/mips/include/asm/atomic.h b/arch/mips/include/asm/atomic.h
new file mode 100644
index 000000000..fd0e09033
--- /dev/null
+++ b/arch/mips/include/asm/atomic.h
@@ -0,0 +1,267 @@
+/*
+ * Atomic operations that C can't guarantee us. Useful for
+ * resource counting etc..
+ *
+ * But use these as seldom as possible since they are much more slower
+ * than regular operations.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 1996, 97, 99, 2000, 03, 04, 06 by Ralf Baechle
+ */
+#ifndef _ASM_ATOMIC_H
+#define _ASM_ATOMIC_H
+
+#include <linux/irqflags.h>
+#include <linux/types.h>
+#include <asm/barrier.h>
+#include <asm/compiler.h>
+#include <asm/cpu-features.h>
+#include <asm/cmpxchg.h>
+#include <asm/llsc.h>
+#include <asm/sync.h>
+#include <asm/war.h>
+
+#define ATOMIC_OPS(pfx, type) \
+static __always_inline type pfx##_read(const pfx##_t *v) \
+{ \
+ return READ_ONCE(v->counter); \
+} \
+ \
+static __always_inline void pfx##_set(pfx##_t *v, type i) \
+{ \
+ WRITE_ONCE(v->counter, i); \
+} \
+ \
+static __always_inline type pfx##_cmpxchg(pfx##_t *v, type o, type n) \
+{ \
+ return cmpxchg(&v->counter, o, n); \
+} \
+ \
+static __always_inline type pfx##_xchg(pfx##_t *v, type n) \
+{ \
+ return xchg(&v->counter, n); \
+}
+
+ATOMIC_OPS(atomic, int)
+
+#ifdef CONFIG_64BIT
+# define ATOMIC64_INIT(i) { (i) }
+ATOMIC_OPS(atomic64, s64)
+#endif
+
+#define ATOMIC_OP(pfx, op, type, c_op, asm_op, ll, sc) \
+static __inline__ void pfx##_##op(type i, pfx##_t * v) \
+{ \
+ type temp; \
+ \
+ if (!kernel_uses_llsc) { \
+ unsigned long flags; \
+ \
+ raw_local_irq_save(flags); \
+ v->counter c_op i; \
+ raw_local_irq_restore(flags); \
+ return; \
+ } \
+ \
+ __asm__ __volatile__( \
+ " .set push \n" \
+ " .set " MIPS_ISA_LEVEL " \n" \
+ " " __SYNC(full, loongson3_war) " \n" \
+ "1: " #ll " %0, %1 # " #pfx "_" #op " \n" \
+ " " #asm_op " %0, %2 \n" \
+ " " #sc " %0, %1 \n" \
+ "\t" __SC_BEQZ "%0, 1b \n" \
+ " .set pop \n" \
+ : "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (v->counter) \
+ : "Ir" (i) : __LLSC_CLOBBER); \
+}
+
+#define ATOMIC_OP_RETURN(pfx, op, type, c_op, asm_op, ll, sc) \
+static __inline__ type pfx##_##op##_return_relaxed(type i, pfx##_t * v) \
+{ \
+ type temp, result; \
+ \
+ if (!kernel_uses_llsc) { \
+ unsigned long flags; \
+ \
+ raw_local_irq_save(flags); \
+ result = v->counter; \
+ result c_op i; \
+ v->counter = result; \
+ raw_local_irq_restore(flags); \
+ return result; \
+ } \
+ \
+ __asm__ __volatile__( \
+ " .set push \n" \
+ " .set " MIPS_ISA_LEVEL " \n" \
+ " " __SYNC(full, loongson3_war) " \n" \
+ "1: " #ll " %1, %2 # " #pfx "_" #op "_return\n" \
+ " " #asm_op " %0, %1, %3 \n" \
+ " " #sc " %0, %2 \n" \
+ "\t" __SC_BEQZ "%0, 1b \n" \
+ " " #asm_op " %0, %1, %3 \n" \
+ " .set pop \n" \
+ : "=&r" (result), "=&r" (temp), \
+ "+" GCC_OFF_SMALL_ASM() (v->counter) \
+ : "Ir" (i) : __LLSC_CLOBBER); \
+ \
+ return result; \
+}
+
+#define ATOMIC_FETCH_OP(pfx, op, type, c_op, asm_op, ll, sc) \
+static __inline__ type pfx##_fetch_##op##_relaxed(type i, pfx##_t * v) \
+{ \
+ int temp, result; \
+ \
+ if (!kernel_uses_llsc) { \
+ unsigned long flags; \
+ \
+ raw_local_irq_save(flags); \
+ result = v->counter; \
+ v->counter c_op i; \
+ raw_local_irq_restore(flags); \
+ return result; \
+ } \
+ \
+ __asm__ __volatile__( \
+ " .set push \n" \
+ " .set " MIPS_ISA_LEVEL " \n" \
+ " " __SYNC(full, loongson3_war) " \n" \
+ "1: " #ll " %1, %2 # " #pfx "_fetch_" #op "\n" \
+ " " #asm_op " %0, %1, %3 \n" \
+ " " #sc " %0, %2 \n" \
+ "\t" __SC_BEQZ "%0, 1b \n" \
+ " .set pop \n" \
+ " move %0, %1 \n" \
+ : "=&r" (result), "=&r" (temp), \
+ "+" GCC_OFF_SMALL_ASM() (v->counter) \
+ : "Ir" (i) : __LLSC_CLOBBER); \
+ \
+ return result; \
+}
+
+#undef ATOMIC_OPS
+#define ATOMIC_OPS(pfx, op, type, c_op, asm_op, ll, sc) \
+ ATOMIC_OP(pfx, op, type, c_op, asm_op, ll, sc) \
+ ATOMIC_OP_RETURN(pfx, op, type, c_op, asm_op, ll, sc) \
+ ATOMIC_FETCH_OP(pfx, op, type, c_op, asm_op, ll, sc)
+
+ATOMIC_OPS(atomic, add, int, +=, addu, ll, sc)
+ATOMIC_OPS(atomic, sub, int, -=, subu, ll, sc)
+
+#define atomic_add_return_relaxed atomic_add_return_relaxed
+#define atomic_sub_return_relaxed atomic_sub_return_relaxed
+#define atomic_fetch_add_relaxed atomic_fetch_add_relaxed
+#define atomic_fetch_sub_relaxed atomic_fetch_sub_relaxed
+
+#ifdef CONFIG_64BIT
+ATOMIC_OPS(atomic64, add, s64, +=, daddu, lld, scd)
+ATOMIC_OPS(atomic64, sub, s64, -=, dsubu, lld, scd)
+# define atomic64_add_return_relaxed atomic64_add_return_relaxed
+# define atomic64_sub_return_relaxed atomic64_sub_return_relaxed
+# define atomic64_fetch_add_relaxed atomic64_fetch_add_relaxed
+# define atomic64_fetch_sub_relaxed atomic64_fetch_sub_relaxed
+#endif /* CONFIG_64BIT */
+
+#undef ATOMIC_OPS
+#define ATOMIC_OPS(pfx, op, type, c_op, asm_op, ll, sc) \
+ ATOMIC_OP(pfx, op, type, c_op, asm_op, ll, sc) \
+ ATOMIC_FETCH_OP(pfx, op, type, c_op, asm_op, ll, sc)
+
+ATOMIC_OPS(atomic, and, int, &=, and, ll, sc)
+ATOMIC_OPS(atomic, or, int, |=, or, ll, sc)
+ATOMIC_OPS(atomic, xor, int, ^=, xor, ll, sc)
+
+#define atomic_fetch_and_relaxed atomic_fetch_and_relaxed
+#define atomic_fetch_or_relaxed atomic_fetch_or_relaxed
+#define atomic_fetch_xor_relaxed atomic_fetch_xor_relaxed
+
+#ifdef CONFIG_64BIT
+ATOMIC_OPS(atomic64, and, s64, &=, and, lld, scd)
+ATOMIC_OPS(atomic64, or, s64, |=, or, lld, scd)
+ATOMIC_OPS(atomic64, xor, s64, ^=, xor, lld, scd)
+# define atomic64_fetch_and_relaxed atomic64_fetch_and_relaxed
+# define atomic64_fetch_or_relaxed atomic64_fetch_or_relaxed
+# define atomic64_fetch_xor_relaxed atomic64_fetch_xor_relaxed
+#endif
+
+#undef ATOMIC_OPS
+#undef ATOMIC_FETCH_OP
+#undef ATOMIC_OP_RETURN
+#undef ATOMIC_OP
+
+/*
+ * atomic_sub_if_positive - conditionally subtract integer from atomic variable
+ * @i: integer value to subtract
+ * @v: pointer of type atomic_t
+ *
+ * Atomically test @v and subtract @i if @v is greater or equal than @i.
+ * The function returns the old value of @v minus @i.
+ */
+#define ATOMIC_SIP_OP(pfx, type, op, ll, sc) \
+static __inline__ type pfx##_sub_if_positive(type i, pfx##_t * v) \
+{ \
+ type temp, result; \
+ \
+ smp_mb__before_atomic(); \
+ \
+ if (!kernel_uses_llsc) { \
+ unsigned long flags; \
+ \
+ raw_local_irq_save(flags); \
+ result = v->counter; \
+ result -= i; \
+ if (result >= 0) \
+ v->counter = result; \
+ raw_local_irq_restore(flags); \
+ smp_mb__after_atomic(); \
+ return result; \
+ } \
+ \
+ __asm__ __volatile__( \
+ " .set push \n" \
+ " .set " MIPS_ISA_LEVEL " \n" \
+ " " __SYNC(full, loongson3_war) " \n" \
+ "1: " #ll " %1, %2 # atomic_sub_if_positive\n" \
+ " .set pop \n" \
+ " " #op " %0, %1, %3 \n" \
+ " move %1, %0 \n" \
+ " bltz %0, 2f \n" \
+ " .set push \n" \
+ " .set " MIPS_ISA_LEVEL " \n" \
+ " " #sc " %1, %2 \n" \
+ " " __SC_BEQZ "%1, 1b \n" \
+ "2: " __SYNC(full, loongson3_war) " \n" \
+ " .set pop \n" \
+ : "=&r" (result), "=&r" (temp), \
+ "+" GCC_OFF_SMALL_ASM() (v->counter) \
+ : "Ir" (i) \
+ : __LLSC_CLOBBER); \
+ \
+ /* \
+ * In the Loongson3 workaround case we already have a \
+ * completion barrier at 2: above, which is needed due to the \
+ * bltz that can branch to code outside of the LL/SC loop. As \
+ * such, we don't need to emit another barrier here. \
+ */ \
+ if (__SYNC_loongson3_war == 0) \
+ smp_mb__after_atomic(); \
+ \
+ return result; \
+}
+
+ATOMIC_SIP_OP(atomic, int, subu, ll, sc)
+#define atomic_dec_if_positive(v) atomic_sub_if_positive(1, v)
+
+#ifdef CONFIG_64BIT
+ATOMIC_SIP_OP(atomic64, s64, dsubu, lld, scd)
+#define atomic64_dec_if_positive(v) atomic64_sub_if_positive(1, v)
+#endif
+
+#undef ATOMIC_SIP_OP
+
+#endif /* _ASM_ATOMIC_H */
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